Display device

ABSTRACT

A display device includes a substrate provided with a plurality of pixels, a circuit element layer provided on the substrate and provided with an auxiliary electrode, an insulating layer provided on the circuit element layer and provided with a plurality of connection electrodes spaced apart from one another and a first trench, a fence structure provided on the plurality of connection electrodes, an organic light emitting layer provided on the fence structure, and a second electrode arranged on the organic light emitting layer, wherein the plurality of connection electrodes are electrically connected with the auxiliary electrode, at least one of the plurality of connection electrodes is exposed from the first trench, and the second electrode is in contact with a connection electrode exposed from the first trench. Therefore, a luminance difference between an outer portion of a panel and a center portion of the panel may be reduced.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit and priority to Korean ApplicationNo. 10-2019-0178089, filed Dec. 30, 2019, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference.

BACKGROUND Technical Field

The present disclosure relates to a display device displaying an image.

Description of the Related Art

With the advancement of the information age, the demand for a displaydevice for displaying an image has increased with various forms.Therefore, various types of display devices such as a liquid crystaldisplay (LCD) device, a light emitting display device, an organic lightemitting display device, a micro light emitting display device, and aquantum dot light emitting display (QLED) device have been recentlyused.

For an organic light emitting display device, in the case that finemetal mask (FMM) technology is used to form red, green and blue pixelsof an organic light emitting layer, it is possible to manufacture asmall-to-medium panel by a mask shadow but it is difficult to apply alarge area to this panel for a problem of sagging of a deposition mask.Therefore, a technology for forming an organic light emitting layerusing a photo process based on a photoresist has been recently issued.

Meanwhile, a cathode electrode provided in an organic light emittingdisplay device is arranged for all pixels as a common layer, and acathode current supplied from an outer portion of a panel to the cathodeelectrode is deteriorated toward a center portion of the panel due toresistance of the cathode electrode, whereby a problem occurs in that aluminance difference occurs between the outer portion of the panel and acenter portion of the panel.

BRIEF SUMMARY

The present disclosure has been made in view of the above problems, andthe present disclosure provides a display device that may reduce aluminance difference between an outer portion of a panel and a centerportion of the panel.

In accordance with one or more embodiments of the present disclosure, adisplay device is provided. The display device includes a substrateprovided with a plurality of pixels, a circuit element layer provided onthe substrate and provided with an auxiliary electrode, an insulatinglayer provided on the circuit element layer and provided with aplurality of connection electrodes spaced apart from one another andwith a first trench, a fence provided on the plurality of connectionelectrodes, an organic light emitting layer provided on the fence, and asecond electrode arranged on the organic light emitting layer, whereinthe plurality of connection electrodes are electrically connected withthe auxiliary electrode, at least one of the plurality of connectionelectrodes is exposed from the first trench, and the second electrode isin contact with a connection electrode exposed from the first trench.

In the display device according to the present disclosure, as theconnection electrode exposed from the trench among the plurality ofconnection electrodes electrically connected with the auxiliaryelectrode is provided to be in contact with the second electrode, aluminance difference between an outer portion of a panel and a centerportion of the panel may be reduced.

In addition to the effects of the present disclosure as mentioned above,additional features of the present disclosure will be clearly understoodby those skilled in the art from the following description of thepresent disclosure.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent disclosure will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a plane view illustrating a display device according to one ormore embodiments of the present disclosure;

FIG. 2 is a cross-sectional view taken along line I-I shown in FIG. 1;

FIG. 3 is a cross-sectional view taken along line II-II shown in FIG. 1;

FIG. 4 is a plane view illustrating another example of an auxiliaryelectrode of a display device according to one or more embodiments ofthe present disclosure;

FIG. 5 is a cross-sectional view illustrating a display device accordingto another embodiment of the present disclosure; and

FIGS. 6A to 6C are views illustrating a display device according toother embodiments of the present disclosure, and relate to ahead-mounted display (HIVID) device.

DETAILED DESCRIPTION

Advantages and features of the present disclosure, and implementationmethods thereof will be clarified through following embodimentsdescribed with reference to the accompanying drawings. The presentdisclosure may, however, be embodied in different forms and should notbe construed as limited to the embodiments set forth herein. Rather,these embodiments are provided so that this disclosure will be thoroughand complete, and will fully convey the scope of the present disclosureto those skilled in the art.

A shape, a size, a ratio, an angle, and a number disclosed in thedrawings for describing embodiments of the present disclosure are merelyan example, and thus, the present disclosure is not limited to theillustrated details. Like reference numerals refer to like elementsthroughout the specification. In the following description, when thedetailed description of the relevant known function or configuration isdetermined to unnecessarily obscure the important point of the presentdisclosure, the detailed description will be omitted. In a case where‘comprise’, ‘have’, and ‘include’ described in the present specificationare used, another part may be added unless ‘only˜’ is used. The terms ofa singular form may include plural forms unless referred to thecontrary.

In construing an element, the element is construed as including an errorrange although there is no explicit description.

In describing a position relationship, for example, when the positionrelationship is described as ‘upon˜’, ‘above˜’, ‘below˜’ and ‘next to˜’,one or more portions may be arranged between two other portions unless‘just’ or ‘direct’ is used.

It will be understood that, although the terms “first”, “second”, etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to partitionone element from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure.

In describing elements of the present disclosure, the terms “first”,“second”, etc. may be used. These terms are intended to identify thecorresponding elements from the other elements, and basis, order, ornumber of the corresponding elements are not limited by these terms. Theexpression that an element is “connected” or “coupled” to anotherelement should be understood that the element may directly be connectedor coupled to another element but may indirectly be connected or coupledto another element unless specially mentioned, or a third element may beinterposed between the corresponding elements.

Features of various embodiments of the present disclosure may bepartially or overall coupled to or combined with each other, and may bevariously inter-operated with each other and driven technically as thoseskilled in the art can sufficiently understand. The embodiments of thepresent disclosure may be carried out independently from each other, ormay be carried out together in co-dependent relationship.

Hereinafter, the embodiments of the display device according to thepresent disclosure will be described in detail with reference to theaccompanying drawings.

Wherever possible, the same reference numbers will be used throughoutthe drawings to refer to the same or like parts.

FIG. 1 is a plane view illustrating a display device according to one ormore embodiments of the present disclosure, FIG. 2 is a cross-sectionalview taken along line I-I shown in FIG. 1, and FIG. 3 is across-sectional view taken along line II-II shown in FIG. 1.

Referring to FIGS. 1 to 3, the display device 1 according to one or moreembodiments of the present disclosure comprises a substrate 2, a circuitelement layer 3, an auxiliary electrode AE, an insulating layer 4, aplurality of connection electrodes M, a reflective panel RP, a firstelectrode 5, a fence structure F (of a fence F), a trench T, an organiclight emitting layer 6, a second electrode 7, and an encapsulation layer8. The trench T may include a first trench T1 and a second trench T2.The first trench T1 according to one example may be arranged between apixel P and an adjacent pixel P (such as a neighboring pixel), and thesecond trench T2 may be arranged in a boundary area among a firstsubpixel 21, a second subpixel 22 and a third subpixel 23 of the pixelP.

The substrate 2 may be a plastic film, a glass substrate, or asemiconductor substrate such as a silicon. The substrate 2 may be madeof a transparent material or an opaque material. However, since thedisplay device 1 according to some embodiments of the present disclosureis provided in a top emission method in which emitted light is emittedto a top portion, an opaque material may be used as a material of thesubstrate 2.

A plurality of pixels P may be provided on the substrate 2. The pixel Pis an area where lights of various colors including white light areemitted, and lights of various colors emitted from the plurality ofpixels P may be combined to make one image. As shown in FIG. 1, theplurality of pixels P may be arranged to be spaced apart from oneanother at a predetermined interval, and a plurality of first trenchesT1 may be arranged between the respective pixels P.

The pixels P may include a first subpixel 21, a second subpixel 22 and athird subpixel 23, which are arranged on the substrate 2. The secondsubpixel 22 according to one example may be arranged to be adjacent toone side of the first subpixel 21. The third subpixel 23 according toone example may be arranged to be adjacent to one side of the secondsubpixel 22. Therefore, the first subpixel 21, the second subpixel 22and the third subpixel 23 may sequentially be arranged on the substrate2.

The first subpixel 21 may be provided to emit red (R) light, the secondsubpixel 22 may be provided to emit green (G) light, and the thirdsubpixel 23 may be provided to emit blue (B) light, but these subpixelsare not limited to this example and may emit lights of various colorsincluding white light. Also, an arrangement sequence of the subpixels21, 22 and 23 may be changed in various ways.

Each of the first subpixel 21, the second subpixel 22 and the thirdsubpixel 23 may be provided to include the reflective panel RP, thefirst electrode 5, the organic light emitting layer 6, and the secondelectrode 7. The second trench T2 may be provided in a boundary areabetween the first subpixel 21 and the second subpixel 22 and a boundaryarea between the second subpixel 22 and the third subpixel 23.

The circuit element layer 3 is arranged on one surface of the substrate2.

A circuit element including a plurality of thin film transistors 31, 32and 33, various types of signal lines, and a capacitor is provided inthe circuit element layer 3 per each of the subpixels 21, 22 and 23. Thesignal lines may include gate lines, data lines, power lines andreference lines, and the thin film transistors 31, 32 and 33 may includea switching thin film transistor, a driving thin film transistor, and asensing thin film transistor. In one embodiment, the subpixels 21, 22and 23 may be defined by a crossing structure of the gate lines,reference lines or reference voltage lines, power supply lines and thedata lines.

The switching thin film transistor is switched in accordance with a gatesignal supplied to the gate line and serves to supply a data voltagesupplied from the data line to the driving thin film transistor.

The driving thin film transistor is switched in accordance with the datavoltage supplied from the switching thin film transistor to generate adata current from a power source supplied from the power line and servesto supply the generated data current to the first electrode 5.

The sensing thin film transistor serves to sense a threshold voltagedeviation of the driving thin film transistor, which is a cause of imagedegradation, and supplies a current of the driving thin film transistorto the reference line in response to a sensing control signal suppliedfrom the gate line or a separate sensing line.

The capacitor serves to maintain the data voltage supplied to thedriving thin film transistor for one frame and is connected to each of agate terminal and a source terminal of the driving thin film transistor.

Referring to FIG. 3, a first thin film transistor 31, a second thin filmtransistor 32, and a third thin film transistor 33 are arranged in thecircuit element layer 3 separately for each of the subpixels 21, 22 and23.

The first thin film transistor 31 according to one example may beconnected to a first sub electrode 51 arranged on the first subpixel 21to apply a driving voltage for emitting light of a color correspondingto the first subpixel 21.

The second thin film transistor 32 according to one example may beconnected to a second sub electrode 52 arranged on the second subpixel22 to apply a driving voltage for emitting light of a colorcorresponding to the second subpixel 22.

The third thin film transistor 33 according to one example may beconnected to a third sub electrode 53 arranged on the third subpixel 23to apply a driving voltage for emitting light of a color correspondingto the third subpixel 23.

Each of the first subpixel 21, the second subpixel 22 and the thirdsubpixel 23 according to one example supplies a predetermined current tothe organic light emitting layer in accordance with the data voltage ofthe data line when a gate signal from the gate line is input theretousing each of the thin film transistors 31, 32 and 33. For this reason,the organic light emitting layer of each of the first subpixel 21, thesecond subpixel 22 and the third subpixel 23 may emit light with apredetermined brightness in accordance with the predetermined current.The auxiliary electrode AE (shown in FIG. 2) may be provided in thecircuit element layer 3.

One function of the auxiliary electrode AE is to prevent voltage drop ofthe second electrode 7 from occurring. The auxiliary electrode AE may bemade of a metal material. The auxiliary electrode AE may be connected tothe second electrode 7 through at least one of the plurality ofconnection electrodes M and apply a voltage supplied from a voltagesupply (not shown) to the second electrode 7 arranged at the center ofthe substrate 2. The voltage supply may be arranged outside thesubstrate 2 (or at an edge of the substrate 2) and therefore may be incontact with the auxiliary electrode AE.

The auxiliary electrode AE according to one example may be arrangedbetween the pixel P and the adjacent pixel P and apply a cathode voltageapplied from the voltage supply (not shown) to the second electrode 7.Therefore, the display device according to the present disclosure mayprevent a luminance difference between the outside of the substrate 2and the center of the substrate 2 from occurring by preventing thecathode voltage at the center of the substrate 2 spaced apart from theoutside of the substrate 2 from being dropped.

The auxiliary electrode AE, as shown in FIG. 2, may be arranged on, butnot limited to, an upper surface of the circuit element layer 3. Thatis, the auxiliary electrode AE may be arranged inside the circuitelement layer 3. If the auxiliary electrode AE is arranged on the uppersurface of the circuit element layer 3, the auxiliary electrode AE mayelectrically be connected to the connection electrode M provided in theinsulating layer 4 through a separate contact electrode. If theauxiliary electrode AE is arranged inside the circuit element layer 3,the auxiliary electrode AE may electrically be connected to theconnection electrode M through a contact electrode arranged in a contacthole provided in the circuit element layer 3 and a contact hole providedin the insulating layer 4. That is, the auxiliary electrode AE mayelectrically be connected to the connection electrode M and apply (ortransfer) a cathode voltage supplied from the voltage supply to theconnection electrode M.

The insulating layer 4 is provided on the upper surface of the circuitelement layer 3.

The insulating layer 4 may be arranged between the first electrode 5 andthe circuit element layer 3. The reflective panel RP and the pluralityof connection electrodes M may be arranged inside or outside theinsulating layer 4.

The reflective panel RP may be arranged in a position corresponding tothe first to third subpixels 21, 22 and 23 to enhance light extractionefficiency of red light, green light and blue light. In more detail, thereflective panel RP reflects light emitted from the organic lightemitting layer 6 of each of the subpixels 21, 22 and 23 toward thesecond electrode 7. As shown in FIG. 3, the reflective panel RP mayinclude a first reflective panel RP1 arranged to overlap the first subelectrode 51, a second reflective panel RP2 arranged to overlap thesecond sub electrode 52 and a third reflective panel RP3 arranged tooverlap the third sub electrode 53. The first to third reflective panelsRP1, RP2 and RP3 may be made of Ag or a metal material that includes Ag.The first to third reflective panels RP1, RP2 and RP3 may respectivelybe connected to the first to third thin film transistors 31, 32 and 33and the first to third sub electrodes 51, 52 and 53 through a separatecontact electrode, whereby a driving voltage supplied from each of thefirst to third thin film transistors 31, 32 and 33 may be applied (ortransferred) to each of the first to third sub electrodes 51, 52 and 53.

The first reflective panel RP1, the second reflective panel RP2 and thethird reflective panel RP3 may respectively be formed to have a widththe same as or greater than that of the first sub electrode 51, thesecond sub electrode 52 and the third sub electrode 53, whereby thelight emitted from the organic light emitting layer 6 may be shieldedfrom progressing toward the substrate 2.

At least one of the plurality of connection electrodes M may be arrangedto adjoin the first trench T1 (or to be exposed to the first trench T1).That is, the plurality of connection electrodes M may be arrangedbetween the pixel P and the adjacent pixel P like the first trench T1.Therefore, the plurality of connection electrodes M are not arrangedinside the first to third subpixels 21, 22 and 23. The plurality ofconnection electrodes M may electrically be connected with the auxiliaryelectrode AE through a separate contact electrode.

The plurality of connection electrodes M applies (or transfers) thecathode voltage applied (or transferred) from the auxiliary electrode AEto the second electrode 7. The plurality of connection electrodes M maybe provided in the insulating layer 4. The connection electrodes Maccording to one example may be arranged inside the insulating layer 4and on an upper surface of the insulating layer 4. The plurality ofconnection electrodes M may be arranged to be spaced apart from oneanother in an up and down direction. In this case, the up and downdirection is a direction where the fence F and the substrate 2 arearranged, wherein a direction toward the fence F may be an up directionand a direction toward the substrate 2 may be a down direction. The upand down direction may mean a second direction orthogonal to a firstdirection if the direction where the first subpixel 21, the secondsubpixel 22 and the third subpixel 23 are arranged is the firstdirection. Therefore, as shown in FIG. 2, the plurality of connectionelectrodes M may be arranged to be spaced apart from one another in adirection from the inside of the insulating layer toward the uppersurface of the insulating layer 4.

A width of each of the plurality of connection electrodes M may beprovided to be narrower than that of the reflective panel RP arranged inthe subpixel. If the width of each of the plurality of connectionelectrodes M is the same as or wider than that of the reflective panelRP, the connection electrode M to which the cathode voltage is applied(or transferred) becomes too close to the first electrode 5 arranged inthe subpixel, whereby short may occur. Therefore, the width of each ofthe plurality of connection electrodes M may be provided to be narrowerthan that of the reflective panel RP arranged in the subpixel. That is,the width of the reflective panel RP may be provided to be wider thanthat of each of the plurality of connection electrodes M.

Meanwhile, the plurality of connection electrodes M may include a firstconnection electrode M1, a second connection electrode M2 and a thirdconnection electrode M3. The first connection electrode M1 may bearranged inside the insulating layer 4. The third connection electrodeM3 may be arranged on the upper surface of the insulating layer 4. Thesecond connection electrode M2 may be arranged inside the insulatinglayer 4 to be located between the first connection electrode M1 and thethird connection electrode M3. Therefore, as shown in FIG. 2, the firstconnection electrode M1, the second connection electrode M2 and thethird connection electrode M3 may be arranged in a line up and downwhile being spaced apart from one another.

The reason why the first connection electrode M1, the second connectionelectrode M2 and the third connection electrode M3 are spaced apart fromone another is that each of the first connection electrode M1, thesecond connection electrode M2 and the third connection electrode M3 isformed of the same material as that of each of the first reflectivepanel RP1, the second reflective panel RP2 and the third reflectivepanel RP3 on the same layer.

First of all, the first to third reflective panels RP1, RP2 and RP3reflects light and therefore may be made of a metal material, and thefirst to third connection electrodes M1, M2 and M3 applies the cathodevoltage and therefore may be made of a metal material. Consequently, thefirst to third reflective panels RP1, RP2 and RP3 and the first to thirdconnection electrodes M1, M2 and M3 may be made of the same material.Although it has been described that the first to third reflective panelsRP1, RP2 and RP3 and the first to third connection electrodes M1, M2 andM3 are made of the metal material, the first to third reflective panelsRP1, RP2 and RP3 and the first to third connection electrodes M1, M2 andM3 may be made of another material, which may apply a voltage whilereflecting light, without limitation to the metal material.

Then, as shown in FIG. 3, the first reflective panel RP1 may be arrangedinside the insulating layer 4, the third reflective panel RP3 may bearranged on the upper surface of the insulating layer 4, and the secondreflective panel RP2 may be arranged inside the insulating layer 4 to belocated between the first reflective panel RP1 and the third reflectivepanel RP3. That is, based on FIG. 3, a first distance SD1 where thefirst reflective panel RP1 is spaced apart from the second electrode 7may be longer than a second distance SD2 where the second reflectivepanel RP2 is spaced apart from the second electrode 7, and the seconddistance SD2 is longer than a third distance SD3 where the thirdreflective panel RP3 is spaced apart from the second electrode 7. Thereason why the first distance SD1, the second distance SD2 and the thirddistance SD3 become short in due order is to extract light of differentcolors by using microcavity characteristic.

The microcavity characteristic means that reinforcing interferenceoccurs to amplify light if a distance between the first to thirdreflective panels RP1, RP2 and RP3 and the second electrode 7 reaches aninteger multiple of a half wavelength V2 of light emitted from each ofthe subpixels 21, 22 and 23 and an amplified level of light iscontinuously increased to improve external extraction efficiency oflight if reflection and re-reflection are repeated. Since the displaydevice 1 according to one embodiment of the present disclosure isprovided to have the microcavity characteristic, the second electrode 7may include a semi-transparent electrode.

Meanwhile, since light extraction efficiency of a long wavelength may beimproved if a spaced distance between the reflective panel RP and thesecond electrode 7 becomes long, light extraction efficiency of redlight in the first distance SD1 may be improved. Since light extractionefficiency of a short wavelength may be improved if a spaced distancebetween the reflective panel RP and the second electrode 7 becomesshort, light extraction efficiency of blue light in the third distanceSD3 may be improved. Since the second distance SD2 is shorter than thefirst distance SD1 and longer than the third distance SD3, lightextraction efficiency of green light may be improved.

Light extraction efficiency of red light may be improved due to thefirst distance SD1 where an upper surface of the first reflective panelRP1 is spaced apart from a lower surface of the second electrode 7,whereby the red light may be emitted from the first subpixel 21. Lightextraction efficiency of green light may be improved due to the seconddistance SD2 where an upper surface of the second reflective panel RP2is spaced apart from the lower surface of the second electrode 7,whereby the green light may be emitted from the second subpixel 22.Light extraction efficiency of blue light may be improved due to thethird distance SD3 where an upper surface of the third reflective panelRP3 is spaced apart from the lower surface of the second electrode 7,whereby the blue light may be emitted from the third subpixel 23.

Consequently, the display device 1 according to one embodiment of thepresent disclosure may be provided to emit light of different colors perfirst to third subpixels 21, 22 and 23 without a color filter becauselight extraction efficiency of different colors per first to thirdsubpixels 21, 22 and 23 may be improved using the microcavitycharacteristic.

In order to obtain the microcavity effect as above, the first reflectivepanel RP1 is arranged inside the insulating layer 4, the thirdreflective panel RP3 is arranged on the upper surface of the insulatinglayer 4, and the second reflective panel RP2 is arranged inside theinsulating layer 4 to be located between the first reflective panel RP1and the third reflective panel RP3. Therefore, the first connectionelectrode M1 formed simultaneously with the first reflective panel RP1may be arranged inside the insulating layer 4, the third connectionelectrode M3 formed simultaneously with the third reflective panel RP3may be arranged on the upper surface of the insulating layer 4, and thesecond connection electrode M2 formed simultaneously with the secondreflective panel RP2 may be arranged inside the insulating layer 4 to belocated between the first connection electrode M1 and the thirdconnection electrode M3. Therefore, the first connection electrode M1,the second connection electrode M2 and the third connection electrode M3may be arranged to be spaced apart from one another at a predeterminedinterval. For example, each of the spaced interval between the firstconnection electrode M1 and the second connection electrode M2 and thespaced interval between the second connection electrode M2 and the thirdconnection electrode M3 may be provided to be 1000 Å or less. As aresult, the first connection electrode M1, the second connectionelectrode M2 and the third connection electrode M3 may be made of thesame material on the same layer like the first reflective panel RP1, thesecond reflective panel RP2 and the third reflective panel RP3 exceptthat they are arranged between the pixel P and the adjacent pixel P andrespectively provided to have a width shorter than that of each of thefirst reflective panel RP1, the second reflective panel RP2 and thethird reflective panel RP3.

Meanwhile, the insulating layer 4 may include a first insulating layer41, a second insulating layer 42, a third insulating layer 43 and afourth insulating layer 44.

The first reflective panel RP1 and the first connection electrode M1 maybe arranged on the upper surface of the first insulating layer 41, thesecond reflective panel RP2 and the second connection electrode M2 maybe arranged on the upper surface of the second insulating layer 42, andthe third reflective panel RP3 and the third connection electrode M3 maybe arranged on the upper surface of the third insulating layer 43. Sidesof the third reflective panel RP3 and the third connection electrode M3may be in contact with the fourth insulating layer 44.

A manufacturing process of the first to third reflective panels RP1, RP2and RP3 and the first to third connection electrodes M1, M2 and M3 is asfollows.

First of all, the first insulating layer 41 is fully deposited on theupper surface of the circuit element layer 3.

Next, a metal material constituting the first reflective panel RP1 andthe first connection electrode M1 is fully deposited on the uppersurface of the first insulating layer 41 and then the first reflectivepanel RP1 is formed by being patterned to correspond to the firstsubpixel 21 through a photo process and an etching process and the firstconnection electrode M1 is formed by being patterned to be arrangedbetween the pixel P and the adjacent pixel P while having a widthsmaller than that of the first reflective panel RP1.

Then, the second insulating layer 42 is fully deposited to cover thefirst reflective panel RP1, the first connection electrode M1 and theupper surface of the first insulating layer 41.

Next, a metal material constituting the second reflective panel RP2 andthe second connection electrode M2 is fully deposited on the uppersurface of the second insulating layer 42 and then the second reflectivepanel RP2 is formed by being patterned to correspond to the secondsubpixel 22 through a photo process and an etching process and thesecond connection electrode M2 is formed by being patterned to bearranged between the pixel P and the adjacent pixel P while having awidth smaller than that of the second reflective panel RP2.

Then, the third insulating layer 43 is fully deposited to cover thesecond reflective panel RP2, the second connection electrode M2 and theupper surface of the second insulating layer 42.

Next, a metal material constituting the third reflective panel RP3 andthe third connection electrode M3 is fully deposited on the uppersurface of the third insulating layer 43 and then the third reflectivepanel RP3 is formed by being patterned to correspond to the thirdsubpixel 23 through a photo process and an etching process and the thirdconnection electrode M3 is formed by being patterned to be arrangedbetween the pixel P and the adjacent pixel P while having a widthsmaller than that of the third reflective panel RP3.

Then, the fourth insulating layer 44 is fully deposited to cover thethird reflective panel RP3, the third connection electrode M3 and theupper surface of the third insulating layer 43. An etching process maybe performed for the entire surface until the upper surface of the thirdreflective panel RP3 and the upper surface of the third connectionelectrode M3 are exposed, whereby the fourth insulating layer 44 may beprovided to be in contact with the sides of the third reflective panelRP3 and the third connection electrode M3.

Through the aforementioned manufacturing process, the first and secondreflective panels RP1 and RP2 and the first and second connectionelectrodes M1 and M2 may be formed inside the insulating layer 4, andthe third reflective panel RP3 and the third connection electrode M3 maybe formed on the upper surface of the insulating layer 4.

Although the process of manufacturing a contact electrode for connectingthe thin film transistors 31, 32 and 33, the first electrode 5 and thereflective panel RP with one another and a contact electrode forconnecting the auxiliary electrode AE with the connection electrodes M1,M2 and M3 has been omitted in the aforementioned manufacturing process,the contact electrode may be formed in the insulating layer 4 through aphoto process and an etching process.

Referring to FIGS. 1 and 2 again, the first trench T1 contacts thesecond electrode 7 with the auxiliary electrode AE through the pluralityof connection electrodes M. The first trench Ti may be arranged betweenthe plurality of pixels P. The first trench T1 may be provided to besmaller than the spaced interval of the pixels P and therefore arrangedto be spaced apart from the pixels P at a predetermined distance. If thefirst trench

T1 is greater than the spaced interval of the pixels P, a size of alight emitting area relatively becomes small, whereby overall lightemitting efficiency may be deteriorated.

The first trench T1 may be formed in such a manner that after the firstelectrode 5 is formed on the fourth insulating layer 44 per subpixels21, 22 and 23, the fence F is fully deposited to cover the firstelectrode 5 and the upper surface of the fourth insulating layer 44which is not covered by the first electrode 5 and then each of the fenceF arranged between the pixel P and the adjacent pixel P, the pluralityof connection electrodes M and the insulating layer 4 is partiallyremoved by being patterned through a photo process and an etchingprocess. Therefore, the sides of the first connection electrode M1, thesecond connection electrode M2 and the third connection electrode M3,which are arranged up and down, may be exposed from the inside of thefirst trench T1.

Meanwhile, since the etching process for forming the first trench T1 isperformed from up to down, the removed area of the third connectionelectrode M3 arranged at an upper side may be greater than the removedarea of the first connection electrode M1 arranged at a lower side.Since this may equally be applied to the insulating layer 4, as shown inFIG. 2, a side of the first trench T1 may be formed to be inclined, anda width of the first trench T1 may be narrow from up to down.

The organic light emitting layer 6 is deposited on the entire surfaceafter the first trench T1 is formed. The organic light emitting layer 6may be inserted into the first trench T1 while covering an upper surfaceof the fence F, thereby partially covering the side of the first trenchT1. Therefore, the organic light emitting layer 6 may partially or fullycover the side of the third connection electrode M3 arranged at theuppermost side of the first trench T1, and at least one of the side ofthe second connection electrode M2 and the side of the first connectionelectrode M1 may be exposed to the outside. At least one of the sides ofthe first connection electrode M1, the second connection electrode M2and the third connection electrode M3, which are exposed to the outside,is in contact with the second electrode 7 deposited during a laterprocess, whereby the cathode voltage applied through the auxiliaryelectrode AE and the plurality of connection electrodes M may be appliedto the second electrode 7 arranged at the center of the substrate 2.

Referring to FIG. 2 again, the organic light emitting layer 6 may bedisconnected from the first trench T1 due to the width W1 of the firsttrench T1. At least a portion of a first stack 61, a charge generationlayer 62 and a second stack 63 of the organic light emitting layer 6 maybe formed on a lower surface (or bottom) of the first trench T1.

As described above, since the organic light emitting layer 6 isdisconnected from the first trench T1, the second electrode 7 depositedduring a later process, as shown in FIG. 2, may be inserted into thefirst trench T1, and therefore may be in contact with the connectionelectrode M exposed from the side of the first trench T1. The secondelectrode 7 may be provided to cover the organic light emitting layer 6formed on the lower surface (or bottom) of the first trench T1, andtherefore may be provided as a common layer without being disconnectedon the substrate 2.

Although FIG. 2 shows that the fence F is arranged on the upper surfaceof the third connection electrode M3, the first electrode 5 may bearranged between the third connection electrode M3 and the fence F.However, in this case, this first electrode 5 may be disconnectedwithout being connected with the first electrode 5 arranged in thesubpixels 21, 22 and 23. This is because that the cathode voltagesupplied to the connection electrode M and an anode voltage supplied persubpixels 21, 22 and 23 may be shorted if the first electrode 5 arrangedbetween the third connection electrode M3 and the fence F is connectedwith the first electrode 5 arranged in the subpixels 21, 22 and 23.Therefore, if the first electrode 5 is arranged near the first trenchT1, this first electrode 5 may be provided to be disconnected from thefirst electrode 5 arranged in the subpixels 21, 22 and 23.

Consequently, the display device 1 according to one embodiment of thepresent disclosure may prevent a cathode voltage drop from occurring andeasily apply the cathode voltage to the center of the substrate 2 byforming the first trench T1 between the pixel P and the adjacent pixel Pand making the connection electrode M exposed from the first trench T1be in contact with the second electrode 7, whereby a luminancedifference between the outside of the substrate 2 and the center of thesubstrate 2 may be reduced.

Meanwhile, the display device 1 according to one embodiment of thepresent disclosure may reduce the number of manufacturing processes byforming the first trench T1 and the second trench T2 together. As shownin FIG. 1, the first trench T1 and the second trench T2 are provided tobe connected with each other, whereby side leakage current may beprevented from occurring among the subpixels 21, 22 and 23 and a cathodevoltage drop of the second electrode may be prevented from occurring.The first trench Ti according to one example may be arranged among foursubpixels as shown in FIG. 1.

Referring to FIG. 3, the first electrode 5 is formed on the insulatinglayer 4 or the reflective panel RP. The first electrode 5 according toone example may be arranged between the reflective panel RP and thesecond electrode 7. In this case, the first electrode 5 may be formed ofa transparent material such as ITO (indium tin oxide), which cantransmit light between the reflective panel RP and the second electrode7. The first electrode 5 may be an anode. The first electrode 5 mayinclude a first sub electrode 51, a second sub electrode 52 and a thirdsub electrode 53.

The first sub electrode 51 may be provided in the first subpixel 21. Thefirst sub electrode 51 may be arranged on the insulating layer 4. Thefirst sub electrode 51 is connected to a source electrode of the firstthin film transistor 31 through a contact electrode provided in acontact hole that partially exposes the first reflective panel RP1arranged inside the insulating layer 4 and a contact hole formed in aportion of the circuit element layer 3.

The second sub electrode 52 may be provided in the second subpixel 22.The second sub electrode 52 may be arranged on the insulating layer 4.The second sub electrode 52 is connected to a source electrode of thesecond thin film transistor 32 through a contact electrode provided in acontact hole that partially exposes the second reflective panel RP2arranged inside the insulating layer 4 to be located above the firstreflective panel RP1 and a contact hole formed in a portion of thecircuit element layer 3.

The third sub electrode 53 may be provided in the third subpixel 23. Thethird sub electrode 53 may be formed on the third reflective panel RP3.The third reflective panel RP3 may be arranged on the upper surface ofthe insulating layer 4 to be located above the second reflective panelRP2. The third sub electrode 53 is connected to a source electrode ofthe third thin film transistor 33 through a contact electrode providedin a contact hole that passes through the third reflective panel RP3 andthe insulating layer 4 arranged on the lower surface of the thirdreflective panel RP3 and a contact hole formed in a portion of thecircuit element layer 3.

In this case, the first to third thin film transistors 31, 32 and 33 maybe N-type TFTs.

If the first to third thin film transistors 31, 32 and 33 are providedas P-type TFTs, each of the first to third sub electrodes 51, 52 and 53may be connected to a drain electrode of each of the first to third thinfilm transistors 31, 32 and 33.

That is, each of the first to third sub electrodes 51, 52 and 53 may beconnected to a source electrode or a drain electrode in accordance withtypes of the first to third thin film transistors 31, 32 and 33.

The display device 1 according to one embodiment of the presentdisclosure is provided in a top emission method, and each of the firstto third sub electrodes 51, 52 and 53 may be made of a transparentelectrode formed of a transparent conductive material. This is becausethat the first to third reflective panels RP1, RP2 and RP3 forreflecting light emitted from the organic light emitting layer 6,progressing to the lower portion toward the second electrode 7 arearranged at the lower portion of the first to third sub electrodes 51,52 and 53.

The first reflective panel RP1 provided in the first subpixel 21, thesecond reflective panel RP2 provided in the second subpixel 22 and thethird reflective panel RP3 provided in the third subpixel 23 may beformed of the substantially same material to have the substantially samethickness.

Referring to FIG. 3 again, the fence F may be provided to cover edges ofthe first electrode 5. In more detail, the fence F may be provided tocover sides of the first sub electrode 51 and a portion of an uppersurface of the first sub electrode 51, cover sides of the second subelectrode 52 and a portion of an upper surface of the second subelectrode 52 and cover sides of the third sub electrode 53 and a portionof an upper surface of the third sub electrode 53. Therefore, the fenceF may partition the first subpixel 21, the second subpixel 22 and thethird subpixel 23 from one another.

In one embodiment, the fence F serves to define the subpixels, that is,a light emitting portion. Also, since an area where the fence F isformed does not emit light, the area may be referred to as a non-lightemitting portion. The fence F may be formed of any one or more of acrylresin, epoxy resin, phenolic resin, polyamide resin, and polyimideresin, or the like. Other suitable materials may be utilized besides theaforementioned resins. The organic light emitting layer 6 is formed onthe first electrode 5 and the fence F.

The second trench T2 may be arranged between fences F arranged in aportion where the first subpixel 21, the second subpixel 22 and thethird subpixel 23 are adjacent to one another. That is, the secondtrench T2 may be provided in a boundary area between the first subpixel21 and the second subpixel 22 and a boundary area between the secondsubpixel 22 and the third subpixel 23. The second trench T2 may beformed between long sides of the first electrode 5 as shown in FIG. 1.

The second trench T2 is formed in the insulating layer 4 in a recessedstructure. In one embodiment, the second trench T2 prevents a sideleakage current from occurring by making a length of a current path belong through the organic light emitting layer 6 among the adjacentsubpixels 21, 22 and 23 or partially disconnecting the organic lightemitting layer 6. The second trench T2 may be formed in, but not limitedto, the insulating layer. The second trench T2 may be formed to beextended to the inside of the circuit element layer 3 below theinsulating layer 4. Like the first trench T1, the side of the secondtrench T2 may be formed to be inclined.

The organic light emitting layer 6 is formed on the first electrode 5.The organic light emitting layer 6 is also formed on the fence F andalso formed on the insulating layer 4 arranged in the boundary areaamong the plurality of subpixels 21, 22 and 23.

The organic light emitting layer 6 may be provided to emit white (W)light. To this end, the organic light emitting layer 6 may include aplurality of stacks emitting light of different colors. In detail, theorganic light emitting layer 6 may include a first stack 61, a secondstack 63 and a charge generation layer (CGL) 62 provided between thefirst stack 61 and the second stack 63.

The first stack 61 is provided on the first electrode 5, and may beformed of a deposited structure of a hole injecting layer HIL, a holetransporting layer HTL, a blue (B) emitting layer EML(B) and an electrontransporting layer ETL, which are deposited in due order.

The charge generation layer (CGL) 62 serves to supply charges to thefirst stack 61 and the second stack 63. The charge generation layer(CGL) 62 may include an N type charge generation layer for supplyingelectrons to the first stack 61 and a P type charge generation layer forsupplying holes to the second stack 63. The N type charge generationlayer may include a metal material as a dopant.

The second stack 63 is provided on the first stack 61, and may be formedof a deposited structure of a hole transporting layer HTL, a yellowgreen (YG) emitting layer EML(YG), an electron transporting layer ETLand an electron injecting layer EIL, which are deposited in due order.

The organic light emitting layer 6 is also formed inside and above thesecond trench T2. According to one embodiment of the present disclosure,as the organic light emitting layer 6 is partially formed inside thesecond trench T2, a long current path between the adjacent subpixels 21,22 and 23 is formed, whereby resistance may be increased and thereforeoccurrence of a leakage current may be reduced.

Particularly, referring to a portion enlarged by an arrow in FIG. 3, thefirst stack 61 is formed at a side inside the second trench T2, and mayalso be formed on a lower surface inside the second trench T2. At thistime, a portion of the first stack 61 formed at the side inside thesecond trench T2 and a portion of the first stack 61 formed on the lowersurface inside the second trench T2 are disconnected from each otherwithout being connected with each other. Therefore, one side inside thesecond trench T2, for example, a portion of the first stack 61 formed ata left side and another side inside the second trench T2, for example, aportion of the first stack 61 formed at a right side are disconnectedfrom each other without being connected with each other. Therefore,charges cannot move through the first stack 61 among the subpixels 21,22 and 23 arranged to adjoin one another by interposing the secondtrench T2.

Also, the charge generation layer 62 may be formed on the first stack 61at the side inside the second trench T2. At this time, one side insidethe second trench T2, for example, a portion of the charge generationlayer 62 formed at a left side and another side inside the second trenchT2, for example, a portion of the charge generation layer 62 formed at aright side are disconnected from each other without being connected witheach other. Therefore, charges cannot move through the charge generationlayer 62 among the subpixels 21, 22 and 23 arranged to adjoin oneanother by interposing the second trench T2.

The second stack 63 may be provided on the charge generation layer 62.Also, the second stack 63 may be provided to be connected from eachother without being disconnected with each other among the subpixels 21,22 and 23 arranged to adjoin one another by interposing the secondtrench T2. Therefore, charges can move through the second stack 63 amongthe subpixels 21, 22 and 23 arranged to adjoin one another byinterposing the second trench T2. However, without limitation to thisexample, a shape of the second trench T2 and a deposition process of theorganic light emitting layer 6 may be controlled appropriately, wherebythe second stack 63 may be provided to be disconnected among thesubpixels 21, 22 and 23 arranged to adjoin one another by interposingthe second trench T2.

Meanwhile, the charge generation layer 62 has conductivity greater thanthe first stack 61 and the second stack 63. Particularly, since the Ntype charge generation layer constituting the charge generation layer 62may include a metal material, the N type charge generation layer hasconductivity greater than the first stack 61 and the second stack 63.

Therefore, charges mainly move through the charge generation layer 62among the subpixels 21, 22 and 23 arranged to adjoin one another, andthe moving amount of charges through the second stack 63 isinsignificant. Therefore, according to one embodiment of the presentdisclosure, the charge generation layer 62 is provided to bedisconnected inside the second trench T2, whereby movement of chargesamong the subpixels 21, 22 and 23 arranged to adjoin one another may bereduced to prevent a leakage current from occurring. Consequently, aportion of the organic light emitting layer 6 may be only disconnectedin the second trench T2. Since the other portion of the organic lightemitting layer 6 is not disconnected from the second trench T2, as shownin FIG. 3, the second electrode 7 may be arranged above the second stack63 without being inserted into the second trench T2.

The second electrode 7 may serve as a cathode of the display device 1 ofthe present disclosure. The second electrode 7 is formed in each of thesubpixels 21, 22 and 23 and among the subpixels 21, 22 and 23 in thesame manner as the organic light emitting layer 6. The second electrode7 is also formed between the pixel P and the adjacent pixel P.Consequently, the second electrode 7 is on the entire surface of thesubstrate 2 as a common layer. The second electrode 7 is connected tothe voltage supply arranged outside the substrate 2 and supplied withthe cathode voltage from the voltage supply, whereby the first electrode5 and an electric field may be formed in the subpixels 21, 22 and 23owned by each of the plurality of pixels P.

Since the display device 1 according to one embodiment of the presentdisclosure is provided in a top emission method and has a microcavitystructure, the second electrode 7 may be made of a semi-transparentelectrode and therefore light extraction effect based on the microcavitymay be obtained per subpixels 21, 22 and 23.

In brief, the second electrode 7, as shown in FIG. 3, may be arrangedabove the organic light emitting layer 6 without being inserted into thesecond trench T2. This is because that a portion of the organic lightemitting layer 6 is only disconnected from the second trench T2 arrangedin the boundary area among the first subpixel 21, the second subpixel 22and the third subpixel 23. That is, as shown in FIG. 3, since the secondstack 63 is connected even in the boundary area among the first to thirdsubpixels 21, 22 and 23, the second electrode 7 is not inserted into thesecond trench T2.

The reason why the second stack 63 may be connected among the first tothird subpixels 21, 22 and 23 is that a width W2 (shown in FIG. 3) ofthe second trench T2 is formed to be narrower than the width W1 (shownin FIG. 2) of the first trench T1. The reason why the width W2 of thesecond trench T2 is formed to be narrower than that of the first trenchT1 is that the first trench T1 contacts the second electrode 7 with atleast one of the plurality of connection electrodes M by allowing thesecond electrode 7 to be arranged inside the first trench T1 bydisconnecting the organic light emitting layer 6, whereas the secondtrench T2 does not need to insert the second electrode 7 into the secondtrench T2. Therefore, since the interval among the first to thirdsubpixels 21, 22 and 23 provided with the second trench T2 may benarrower than the interval between the pixels P, it may be morefavorable to embody high resolution.

Consequently, the second electrode 7 may be in contact with theauxiliary electrode AE to reduce a luminance difference between theoutside of the substrate 2 and the center of the substrate 2. Further,the first trench T1 may be provided to be wider than the second trenchT2. Since the cathode voltage drop of the second electrode 7 may beavoided by the first trench T1, the second trench T2 does not need to beprovided at the same width as that of the first trench T1 and may beprovided to be narrower than the first trench T1, whereby the intervalamong the subpixels 21, 22 and 23 may be reduced to embody highresolution more easily.

The width W1 of the first trench Ti according to one example may be 0.15μm or more and 0.2 μm or less. If the width of the first trench T1 isless than 0.15 μm, the organic light emitting layer 6 is not fullydisconnected, whereby the second electrode 7 is not inserted into thefirst trench T1 and therefore the second electrode 7 is not in contactwith at least one of the plurality of connection electrodes M. For thisreason, the cathode voltage drop occurs toward the center of thesubstrate 2 and therefore a luminance difference between the outside ofthe substrate 2 and the center of the substrate 2 may occur. If thewidth of the first trench T1 exceeds 0.2 μm, a portion of the organiclight emitting layer 6 covers both a left side and a right side of thefirst trench T1, whereby the second electrode 7 may not be in contactwith at least one of the plurality of connection electrodes M.Therefore, in the display device 1 according to one embodiment of thepresent disclosure, the width W1 of the first trench T1 is provided tobe 0.15 μm or more and 0.2 μm or less and therefore the second electrode7 is inserted into the first trench T1, whereby the second electrode 7may be in contact with at least one of the plurality of connectionelectrodes M and therefore may be applied with the cathode voltage fromthe auxiliary electrode AE.

Meanwhile, the depth D1 (shown in FIG. 2) of the first trench T1according to one example may be 0.2 μm or more and 0.4 μm or less. Ifthe depth of the first trench T1 is less than 0.2 μm, a portion of theorganic light emitting layer 6 covers all of the plurality of connectionelectrodes M exposed to the first trench T1 and therefore the secondelectrode 7 may not be in contact with at least one of the plurality ofconnection electrodes M. For another example, if the depth of the firsttrench T1 is less than 0.2 μm, a portion of the organic light emittinglayer 6 covers the third connection electrode M3 and the secondconnection electrode M2 and the first connection electrode M1 is notexposed from the insulating layer 4, whereby the second electrode 7 maynot be in contact with at least one of the plurality of connectionelectrodes M. Consequently, if the depth of the first trench T1 is lessthan 0.2 μm, the second electrode 7 may not be in contact with at leastone of the plurality of connection electrodes M. If the depth D1 of thefirst trench T1 exceeds 0.4 μm, the auxiliary electrode AE may be etchedwhen the first trench T1 is formed, whereby a thickness of the auxiliaryelectrode AE may become thin or be disconnected. For this reason, sinceresistance of the auxiliary electrode AE is increased, a cathode voltagedrop prevention ratio through the auxiliary electrode AE becomes smallor the cathode voltage drop not be prevented from occurring. Therefore,in the display device 1 according to one embodiment of the presentdisclosure, as the depth D1 of the first trench T1 may be provided to be0.2 μm or more and 0.4 μm or less, the auxiliary electrode AE may beprevented from being damaged and at least one of the plurality ofconnection electrodes M may be exposed from the organic light emittinglayer 6 or the insulating layer 4, whereby the second electrode 7 may bein contact with at least one of the plurality of connection electrodes Mand therefore may be applied with the cathode voltage from the auxiliaryelectrode AE.

As described above, since the second trench T2 is formed to be narrowerthan the first trench T1, the depth D2 of the second trench T2 may beprovided to be lower than the depth D1 of the first trench T1.

Referring to FIG. 3 again, the encapsulation layer 8 may be formed onthe second electrode 7. In one embodiment, the encapsulation layer 8serves to prevent oxygen or water from being permeated into the organiclight emitting layer 6 and the second electrode 7. To this end, theencapsulation layer 8 may include at least one inorganic film and atleast one organic film.

For example, the encapsulation layer 8 may include a first inorganicfilm, an organic film, and a second inorganic film. In this case, thefirst inorganic film is formed to cover the second electrode 7. Theorganic film is formed to cover the first inorganic film. It ispreferable that the organic film is formed at a length long enough toprevent particles from being permeated into the organic light emittinglayer 6 and the second electrode 7 by passing through the firstinorganic film. The second inorganic film is formed to cover the organicfilm.

FIG. 4 is a plane view illustrating another example of an auxiliaryelectrode of a display device according to one or more embodiments ofthe present disclosure.

Referring to FIG. 4, a portion of the auxiliary electrode AE may beprovided to overlap the pixel P. That is, as the auxiliary electrode AEis provided to be wider than that of FIG. 1, one side of the auxiliaryelectrode AE may be overlapped with the pixel P and the other side ofthe auxiliary electrode AE may be overlapped with another pixel Padjacent to the above pixel P. Therefore, as shown in FIG. 4, theauxiliary electrode AE may include a first overlap area OA1 overlappedwith the pixel P arranged at an upper side, and a second overlap areaOA2 overlapped with the pixel arranged at a lower side.

In more detail, the pixel P arranged at the upper side based on FIG. 4may include a first subpixel 21, a second subpixel 22 and a thirdsubpixel 23, each of which may include a first sub electrode 51, asecond sub electrode 52 and a third sub electrode 53. The pixel Parranged at the lower side based on FIG. 4 may include a fourth subpixel24, a fifth subpixel 25 and a sixth subpixel 26, each of which mayinclude a fourth sub electrode 54, a fifth sub electrode 55 and a sixthsub electrode 56. The pixel P arranged at the lower side based on FIG. 4may be the pixel P located in a third direction vertical to each of afirst direction and a second direction based on the pixel arranged atthe upper side.

One side of the auxiliary electrode AE may be overlapped with a fence Farranged from the first subpixel 21 to the fourth subpixel 24, and thefirst sub electrode 51 overlapped with the fence F. In this case, oneside of the auxiliary electrode AE may also be overlapped with the firstreflective panel RP1 overlapped with the fence F.

Also, one side of the auxiliary electrode AE may be overlapped with afence F arranged from the second subpixel 22 to the fifth subpixel 25,and the second sub electrode 52 overlapped with the fence F. In thiscase, one side of the auxiliary electrode

AE may also be overlapped with the second reflective panel RP2overlapped with the fence F.

Also, one side of the auxiliary electrode AE may be overlapped with afence F arranged from the third subpixel 23 to the sixth subpixel 26,and the third sub electrode 53 overlapped with the fence F. In thiscase, one side of the auxiliary electrode AE may also be overlapped withthe third reflective panel RP3 overlapped with the fence F.

Meanwhile, the other side of the auxiliary electrode AE may beoverlapped with a fence F arranged from the fourth subpixel 24 to thefirst subpixel 21, and the fourth sub electrode 54 overlapped with thefence F. In this case, the other side of the auxiliary electrode AE mayalso be overlapped with a fourth reflective panel (not shown) overlappedwith the fence F.

Also, the other side of the auxiliary electrode AE may be overlappedwith a fence F arranged from the fifth subpixel 25 to the secondsubpixel 22, and the fifth sub electrode 55 overlapped with the fence F.In this case, the other side of the auxiliary electrode AE may also beoverlapped with a fifth reflective panel (not shown) overlapped with thefence F.

Also, the other side of the auxiliary electrode AE may be overlappedwith a fence F arranged from the sixth subpixel 26 to the third subpixel23, and the sixth sub electrode 56 overlapped with the fence F. In thiscase, the other side of the auxiliary electrode AE may also beoverlapped with a sixth reflective panel (not shown) overlapped with thefence F.

However, without limitation to this case, one side of the auxiliaryelectrode AE may be overlapped with a portion of a light emitting areaof the first subpixel 21, the second subpixel 22 and the third subpixel23, and the other side of the auxiliary electrode AE may be overlappedwith a portion of a light emitting area of the fourth subpixel 24, thefifth subpixel 25 and the sixth subpixel 26.

Since the auxiliary electrode AE is arranged below the insulating layer4, even though the auxiliary electrode AE is overlapped with the pixelP, the auxiliary electrode AE may not interfere with a user who views animage. Since a resistance value of the auxiliary electrode AE is morelowered if a width of the auxiliary electrode AE becomes wide, thecathode voltage may be applied to the second electrode 7 located at thecenter of the substrate 2 more easily.

The auxiliary electrode AE may be provided to be arranged among theplurality of pixels P or between two pixels P. If the auxiliaryelectrode AE is arranged among the plurality of pixels P, that is, ifeach of the pixels P is matched with the auxiliary electrode AE at aratio of 1:1 or 1:2, the cathode voltage is applied to each pixel Pthrough the auxiliary electrode AE, whereby a luminance differencebetween the outside of the substrate 2 and the center of the substrate 2may be more reduced. On the other hand, if the auxiliary electrode AE isprovided to be arranged between two pixels P, that is, if two pixels Pshare one auxiliary electrode AE, the cathode voltage may not be appliedto each pixel P more easily than the case that the auxiliary electrodeAE is arranged among the pixels P, but the interval between the pixelswhere the auxiliary electrode AE is not arranged may be reduced, wherebyit may be favorable to embody high resolution.

FIG. 5 is a cross-sectional view taken along a direction same as thedirection of line II-II shown in FIG. 1 illustrating a display deviceaccording to another embodiment of the present disclosure.

Referring to FIG. 5, the display device 1 according to anotherembodiment of the present disclosure is the substantially same as thedisplay device based on FIG. 3 except that a color filter layer 9 isprovided on the encapsulation layer 8 of each of the first subpixel 21,the second subpixel 22 and the third subpixel 23. Therefore, the samereference numerals will be given to the same elements, and differentelements will be mainly described hereinafter.

In case of the display device based on FIG. 3, as the spaced distancebetween the second electrode 7 and the reflective panel RP is varied perfirst to third subpixels 21, 22 and 23, red light is emitted from thefirst subpixel 21, green light is emitted from the second subpixel 22,and blue light is emitted from the third subpixel 23. That is, thedisplay device based on FIG. 3 improves light extraction efficiency ofdifferent colors per subpixels 21, 22 and 23 by using the microcavityeffect.

On the other hand, in case of the display device according to anotherembodiment of FIG. 5, the color filter layer 9 is arranged on theencapsulation layer 8, whereby a problem of a color viewing angle oflight emitted from each of the subpixels 21, 22 and 23 may be solved. Inmore detail, since the display device based on FIG. 3 is provided toemit light of different colors per subpixels 21, 22 and 23 by using themicrocavity structure without a color filter, a distance between thesecond electrode 7 and the reflective panel RP in a vertical directionper subpixel may be formed differently from a distance between thesecond electrode 7 and the reflective panel RP in a diagonal direction.For example, a distance SD1 between the second electrode 7 and the firstreflective panel RP1 in a vertical direction from the first subpixel 21to an upper surface of the reflective panel RP is shorter than adistance between the second electrode 7 and the first reflective panelRP1 in an inclined direction not the direction vertical to the uppersurface of the reflective panel RP. Therefore, a user located in thevertical direction may view a red color, whereas a user located in theinclined direction may view another color not the red color.Consequently, in case of the display device based on FIG. 3, a problemof a color viewing angle may occur in that different colors may be seento a user depending on a position where the user views subpixel, thatis, a viewing angle.

However, in case of the display device according to another embodimentof FIG. 5, the color filter layer 9 is provided on the encapsulationlayer 8, whereby the problem of the color viewing angle may be solved.The color filter layer 9 of the display device according to anotherembodiment of FIG. 5 may include a first color filter 91 provided tocorrespond to the first subpixel 21, a second color filter 92 providedto correspond to the second subpixel 22, and a third color filter 93provided to correspond to the third subpixel 23.

The first color filter 91 is to filter light of the other colors to emitonly red (R) light, and may be a red color filter. Since the first colorfilter 91 is provided at a size corresponding to the first subpixel 21and emits only red (R) light having light extraction efficiency improvedby the microcavity effect from the first subpixel 21, even though theviewing angle is varied as described above, light of the other colorsmay be filtered by the first color filter 91, whereby the user may viewonly red light.

The second color filter 92 is to filter light of the other colors toemit only green (G) light, and may be a green color filter. Since thesecond color filter 92 is provided at a size corresponding to the secondsubpixel 22 and emits only green (G) light having light extractionefficiency improved by the microcavity effect from the second subpixel22, even though the viewing angle is varied as described above, light ofthe other colors may be filtered by the second color filter 92, wherebythe user may view only green light.

The third color filter 93 is to filter light of the other colors to emitonly blue (B) light, and may be a blue color filter. Since the thirdcolor filter 93 is provided at a size corresponding to the thirdsubpixel 23 and emits only blue (B) light having light extractionefficiency improved by the microcavity effect from the third subpixel23, even though the viewing angle is varied as described above, light ofthe other colors may be filtered by the third color filter 93, wherebythe user may view only blue light.

Consequently, in the display device 1 according to another embodiment ofthe present disclosure, as the color filter layer 9 is provided on theencapsulation layer 8 of each of the first subpixel 21, the secondsubpixel 22 and the third subpixel 23, the color filter layer 9 shieldslight of the other color emitted due to a distance difference betweenthe second electrode 7 and the reflective panel RP depending on theviewing angle, whereby the problem of the color viewing angle may besolved.

FIGS. 6A to 6C are views illustrating a display device according toother embodiments of the present disclosure and relate to a head mounteddisplay (HIVID) device. FIG. 6A is a perspective view, FIG. 6B is aplane view of a virtual reality (VR) structure, and FIG. 6C is across-sectional schematic view of an augmented reality (AR) structure.

As will be aware of it from FIG. 6A, a head mounted display deviceaccording to present disclosure comprises a storage case 10 and a headmounted band 12.

The storage case 10 stores elements such as a display device, a lensarray, and an ocular lens therein.

The head mounted band 12 is removably attached to the storage case 10.The head mounted band 12 is formed to surround an upper surface and bothsides of a user's head, but is not limited to this example. The headmounted band 12 is to fix a head mounted display device to a user'shead. In other embodiments, the head mounted band 12 may be replacedwith a structure of a shape of a glasses frame or a helmet shape.

As will be aware from FIG. 6B, the head mounted display device of avirtual reality (VR) structure according to the present disclosure mayinclude a left eye display device 2 a, a right eye display device 2 b, alens array 11, a left eye ocular lens 20 a, and a right eye ocular lens20 b.

The left eye display device 2 a, the right eye display device 2 b, thelens array 11, the left eye ocular lens 20 a and the right eye ocularlens 20 b are stored in the storage case 10 described above.

The left eye display device 2 a and the right eye display device 2 b maydisplay the substantially same image, and in this case, a user may viewa 2D image.

Alternatively, the left eye display device 2 a may display a left eyeimage and the right eye display device 2 b may display a right eyeimage, and in this case, a user may view a 3D image. Each of the lefteye display device 2 a and the right eye display device 2 b may becomprised of a display device according to FIGS. 1 to 5 described above.For example, each of the left eye display device 2 a and the right eyedisplay device 2 b may be an organic light emitting display device.

Each of the left eye display device 2 a and the right eye display device2 b may include a plurality of subpixels, a circuit element layer 3, aninsulating layer 4, an auxiliary electrode AE, a trench T, a reflectivepanel RP, a first electrode 5, a fence F, an organic light emittinglayer 6, a second electrode 7, and an encapsulation layer 8, and maydisplay various images by combining colors of light emitted from each ofthe subpixels in various manners.

The lens array 11 may be provided between the left eye ocular lens 20 aand the left eye display device 2 a by being spaced apart from each ofthe left eye ocular lens 20 a and the left eye display device 2 a. Thatis, the lens array 11 may be arranged in front of the left eye ocularlens 20 a and behind the left eye display device 2 a. Also, the lensarray 11 may be provided between the right eye ocular lens 20 b and theright eye display device 2 b by being spaced apart from each of theright eye ocular lens 20 b and the right eye display device 2 b. Thatis, the lens array 11 may be arranged in front of the right eye ocularlens 20 b and behind the right eye display device 2 b.

In some embodiments, the lens array 11 may be a micro lens array. Inother embodiments, the lens array 11 may be replaced with a pin holearray. Due to the lens array 11, images displayed on the left eyedisplay device 2 a or the right eye display device 2 b may be viewed tobe magnified to a user.

A left eye LE of a user may be arranged in the left eye ocular lens 20a, and a right eye RE of a user may be arranged in the right eye ocularlens 20 b.

As will be aware from FIG. 6C, a head mounted display device of an ARstructure according to the present disclosure includes a left eyedisplay device 2 a, a lens array 11, a left eye ocular lens 20 a, atransmissive reflection portion 13, and a transmissive window 14.Although only a structure for a left eye is shown in FIG. 6C forconvenience, a structure for a right eye is the substantially same asthe structure for the left eye.

The left eye display device 2 a, the lens array 11, the left eye ocularlens 20 a, the transmissive reflection portion 13, and the transmissivewindow 14 are stored in the aforementioned storage case 10.

The left eye display device 2 a may be arranged at one side of thetransmissive reflection portion 13, for example, at an upper side,without covering the transmissive window 14. Therefore, the left eyedisplay device 2 a may provide the transmissive reflection portion 13with an image without covering an outer background viewed through thetransmissive window 14.

The left eye display device 2 a may be comprised of an organic displaydevice according to FIGS. 1 to 5 described above. In this case, the topportion corresponding to the surface where images are displayed in FIGS.1 to 5, for example, the encapsulation layer 8 or a color filter layer 9faces the transmissive reflection portion 13.

The lens array 11 may be provided between the left eye ocular lens 20 aand the transmissive reflection portion 13.

A left eye of a user is arranged in the left eye ocular lens 20 a.

The transmissive reflection portion 13 is arranged between the lensarray 11 and the transmissive window 14. The transmissive reflectionportion 13 may include a reflective surface 13 a which transmits aportion of light and reflects another portion of light. The reflectivesurface 13 a is formed to allow an image displayed on the left eyedisplay device 2 a to proceed to the lens array 11. Therefore, a usermay view all of images displayed on the left eye display device 2 a andan outer background through the transmissive window 14. That is, sincethe user may view one image by overlapping background in reality withvirtual images, augmented reality (AR) may be embodied.

The transmissive window 14 is arranged in front of the transmissivereflection portion 13.

It will be apparent to those skilled in the art that the presentdisclosure described above is not limited by the above-describedembodiments and the accompanying drawings and that varioussubstitutions, modifications, and variations can be made in the presentdisclosure without departing from the spirit or scope of the disclosure.Consequently, the scope of the present disclosure is intended toencompass all variations or modifications derived from the meaning,scope, and equivalent concept that fall within the scope of the presentdisclosure.

The various embodiments described above can be combined to providefurther embodiments. These and other changes can be made to theembodiments in light of the above-detailed description. In general, inthe following claims, the terms used should not be construed to limitthe claims to the specific embodiments disclosed in the specificationand the claims, but should be construed to include all possibleembodiments along with the full scope of equivalents to which suchclaims are entitled. Accordingly, the claims are not limited by thedisclosure.

1. A display device, comprising: a substrate having thereon a pluralityof pixels; a circuit element layer on the substrate and provided with anauxiliary electrode; an insulating layer on the circuit element layer; aplurality of connection electrodes positioned in the insulating layerand spaced apart from one another; a first trench positioned in theinsulating layer; a fence structure on the plurality of connectionelectrodes; an organic light emitting layer on the fence structure; anda second electrode on the organic light emitting layer, wherein theplurality of connection electrodes are electrically connected with theauxiliary electrode, at least one of the plurality of connectionelectrodes is exposed from the first trench, and the second electrode isin contact with a connection electrode exposed from the first trench. 2.The display device of claim 1, wherein the first trench is arrangedbetween the pixels.
 3. The display device of claim 1, wherein theorganic light emitting layer is disconnected from the first trench. 4.The display device of claim 1, wherein the second electrode is placed inthe first trench.
 5. The display device of claim 1, wherein the firsttrench has a width of 0.15 p.m or more and 0.2 μm or less.
 6. Thedisplay device of claim 1, wherein the first trench has a depth of 0.2μm or more and 0.4 μm or less.
 7. The display device of claim 1, whereina portion of the auxiliary electrode is overlapped with each of thepixels.
 8. The display device of claim 1, wherein each of the pixelsincludes: a first subpixel, a second subpixel and a third subpixelprovided on the substrate; a thin film transistor provided in thecircuit element layer per first subpixel, second subpixel and thirdsubpixel; a reflective panel arranged inside or outside the insulatinglayer to correspond to each of the first subpixel, the second subpixeland the third subpixel; and a first electrode provided on the insulatinglayer or the reflective panel, including a first sub electrode providedin the first subpixel, a second sub electrode provided in the secondsubpixel and a third sub electrode provided in the third subpixel,wherein the fence structure covers edges of the first electrode, theorganic light emitting layer is arranged on the first electrode and thefence structure, a distance between an upper surface of a reflectivepanel provided in the first subpixel and a lower surface of the secondelectrode is longer than a distance between an upper surface of areflective panel provided in the second subpixel and a lower surface ofthe second electrode, and a distance between the upper surface of thereflective panel provided in the second subpixel and the lower surfaceof the second electrode is longer than a distance between an uppersurface of a reflective panel provided in the third subpixel and thelower surface of the second electrode.
 9. The display device of claim 8,wherein the width of the reflective panel is wider than that of each ofthe plurality of connection electrodes.
 10. The display device of claim8, wherein the reflective panel includes a first reflective paneloverlapping the first sub electrode, a second reflective paneloverlapping the second sub electrode, and a third reflective paneloverlapping the third sub electrode, the first reflective panel isarranged inside the insulating layer, the third reflective panel is onan upper surface of the insulating layer, and the second reflectivepanel is arranged inside the insulating layer to be located between thefirst reflective panel and the third reflective panel.
 11. The displaydevice of claim 10, wherein the plurality of connection electrodesinclude: a first connection electrode arranged inside the insulatinglayer; a second connection electrode arranged inside the insulatinglayer; a third connection electrode arranged on the upper surface of theinsulating layer, wherein the second connection electrode is between thefirst connection electrode and the third connection electrode, and thefirst connection electrode, the second connection electrode, the thirdconnection electrode, the first reflective panel, the second reflectivepanel and the third reflective panel are made of the same orsubstantially the same material.
 12. The display device of claim 8,wherein the first subpixel is provided to emit red light, the secondsubpixel is provided to emit green light, and the third subpixel isprovided to emit blue light.
 13. The display device of claim 8, furthercomprising a second trench in a boundary area among the first subpixel,the second subpixel and the third subpixel, wherein a width of thesecond trench is narrower than that of the first trench.
 14. The displaydevice of claim 13, wherein the organic light emitting layer ispartially disconnected from the second trench.
 15. The display device ofclaim 13, wherein the second electrode is not formed within the secondtrench.
 16. The display device of claim 8, further comprising: anencapsulation layer on the second electrode; and a color filter layer onthe encapsulation layer, wherein the color filter layer includes a firstcolor filter provided to correspond to the first subpixel, a secondcolor filter provided to correspond to the second subpixel, and a thirdcolor filter provided to correspond to the third subpixel.
 17. Thedisplay device of claim 1, further comprising a lens array spaced apartfrom the substrate, and a storage case storing the substrate and thelens array.
 18. The display device of claim 1, wherein a side of thefirst trench is inclined, and a width of the first trench becomesnarrower from an upper portion of the first trench to a lower portion ofthe first trench.
 19. The display device of claim 1, wherein the secondelectrode includes a semi-transparent electrode.
 20. The display deviceof claim 13, wherein the first trench and the second trench areconnected with each other.